化简：(x-1/2y-1)(x-1/2y+1)-(x-1/2y-1)^2^2 不是乘2,是指2的次方

[(-x-y)(-x+y)-(x+y)^2-x(y-y^2)}÷1/2y 化简(2x+y)(2x-y)-(x+2y)(x-2y-1) 2x分之1- x+y分之1(2x分之x+y -x-y)化简 化简1/2x-1/x+y（x+y/2x-x-y） 化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1 1、y-x/x²-y²2、(x-y)(y-z)(z-x)/(z-y)(y-x)(x-z) 1/(x-y)+1/(x+y)+2x/(x^2+y^2)+4x^3/(x^4+y^4)化简 化简：[(2x-y)平方+（2x+y)(2x-y)-4x(x-y+1)]÷2x (x-y)(2x-y-1) (x/x+y-x/y-x-2xy/x.x-y.y)/(1/x-1/y) 分式化简 x²/xy-x/y 3x/4x+y - x-2y/4x+y (1-y/y+x)÷x/y²-x² 化简 3x(x^2-x-1)-(x+1)(3x^-x) X^3(x-y)+x(y-x) 2y(x+二分之一y)-[(x+y)(x-y)+2y(y+x)],其中|x-1|=2 （x-y)(x+y)-(x+y)^2+2y(y-x),其中x=1,y=3. 化简,求值：[(x/y)-(y/x)]除以[(x/y)+(y/x)-2]除以[1+(y/x)],其中x=1/2,y=1/3 化简：(x-y)/(2x+1) * [(2x+1)/(x+y) - (2xy+y)/(y方－x方)]+y/(x+y) 若x-y=1 化简（x+y)(x^2+y^2)(x^4+y^4)(x^8+y^8)(x^16+y^16) 已知x+y=a,2x-y=-2a,求[（x/y-y/x)/(x+y)-x(1/x-1/y)]/[(x+1)/y]的值